US20150365571A1

US20150365571A1 - Imaging module, insulating-tube-attached imaging module, lens-attached imaging module, and endoscope

Info

Publication number: US20150365571A1
Application number: US14/761,757
Authority: US
Inventors: Hideyuki Wada; Kenichi Nakatate
Original assignee: Fujikura Ltd
Current assignee: Fujikura Ltd
Priority date: 2013-02-13
Filing date: 2014-02-13
Publication date: 2015-12-17
Anticipated expiration: 2034-02-13
Also published as: US9667843B2; DE112014000800T5; WO2014126144A1; JP6012842B2; JPWO2014126144A1

Abstract

An imaging module of the invention includes: an electrical cable; a solid-state image sensing device; and a three-dimensional wiring base in which a mount surface is provided on a molded product. The mount surface has two opposed apexes which sandwich a central portion therebetween and is molded so that the distance between the two apexes is the longest in distances between two points on sides of the mount surface, a cross section parallel to the mount surface of the three-dimensional wiring base is equal to the mount surface or smaller than the mount surface, and the distance between two points that is the longest in distances on sides of a shape in a plan view of the solid-state image sensing device is equal to or shorter than the distance between the two apexes.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This is the U.S. National Phase Application under 35 U.S.C. §371 of International Patent Application No. PCT/JP2014/053313 filed Feb. 13, 2014, which designated the United States and was published in a language other than English, which claims the benefit of Japanese Patent Application No. 2013-025475 filed on Feb. 13, 2013, both of them are incorporated by reference herein. The International Application was published in Japanese on Aug. 21, 2014 as W02014/126144 A1 under PCT Article 21(2).

BACKGROUND OF THE INVENTION

1. Field of the Invention
The present invention relates to an imaging module configured so that a solid-state image sensing device is packaged on a three-dimensional wiring base, an insulating-tube-attached imaging module configured by using the imaging module, a lens-attached imaging module, and an endoscope.
2. Description of the Related Art
It is essential for an imaging module used in an endoscope to be small.
The imaging module is configured to include a small solid-state image sensing device such as a CCD (Charge Coupled Device) chip or a CMOS (Complementary Metal Oxide Semiconductor) chip and a wiring base that has a surface on which wirings are formed and is used to package the above-mentioned solid-state image sensing device thereonto.
In the above-described solid-state image sensing device, for example, stacked chips have a configuration in which terminals used to connect a wiring base to the opposite side of a light-receiving face via through-hole interconnections (TSV: Trough Silicon Via) are provided.
On the other hand, as the wiring base on which the solid-state image sensing device is mounted, for example, a three-dimensional wiring base is used.
The three-dimensional wiring base is used to three-dimensionally package electronic components thereon and has a structure in which wirings are formed on a surface of a three-dimensional molded product made of resin, ceramic, or the like.
For example, in an imaging module used in an endoscope, a three-dimensional wiring base is molded in a substantially cylindrical shape, and a circular mount surface is provided on a substantially cylindrical-shaped front end.
For example, imaging modules that are formed by use of the aforementioned solid-state image sensing device and the three-dimensional wiring base and are used in endoscopes, are disclosed in Japanese Unexamined Patent Application, First Publication No. 2001-27734, Japanese Unexamined Patent Application, First Publication No. 2009-201762, Japanese Unexamined Patent Application, First Publication No. 2011-240053, or Japanese Unexamined Patent Application, First Publication No. 2012-254176.
However, in the above-mentioned conventional technologies, the imaging module is covered with the cylindrical insulating tube in order to ensure electrical insulation between surface wirings formed on the three-dimensional wiring base; however, since the mount surface of the three-dimensional wiring base is formed in a circular shape, the entire outer-periphery of the mount surface is caught by the inner surface of the insulating tube at the time of inserting the imaging module into the insulating tube, there is a problem in that it is difficult to insert it into the insulating tube.
Additionally, in the above-mentioned conventional technologies, it is necessary to provide, on the surface of the mount surface, an alignment mark that serves as a mark used to package a solid-state image sensing device on the right position; however, since the mount surface of a three-dimensional wiring base used in an imaging module of an endoscope is extremely small, it is extremely difficult to provide the alignment mark on the mount surface.

SUMMARY OF THE INVENTION

The invention was made in view of the above-described situation, and has an object to cause a solid-state image sensing device to be easily inserted into an insulating tube and to provide an alignment mark used to attach the solid-state image sensing device to the right position.
In order to achieve the object, an imaging module according to a first aspect of the invention includes: an electrical cable; a solid-state image sensing device having a light-receiving face perpendicular to an axis direction of a front end of the electrical cable; and a three-dimensional wiring base in which a wiring is formed on a surface of a molded product extending in the axis direction, the electrical cable is electrically connected to the solid-state image sensing device via the wiring, and a mount surface used to package the solid-state image sensing device thereon is provided on a front end of the molded product, wherein the mount surface has two opposed apexes which sandwich a central portion therebetween and is molded so that the distance between the two apexes is the longest in the distances between two points on sides of the mount surface, a cross section parallel to the mount surface of the three-dimensional wiring base is equal to the mount surface or smaller than the mount surface, and the distance between two points that is the longest in the distances on sides of a shape in a plan view of the solid-state image sensing device is equal to or shorter than the distance between the two apexes.
In the imaging module according to the first aspect of the invention, it is preferable that the mount surface be formed in a hexagonal shape.
In the imaging module according to the first aspect of the invention, it is preferable that the molded product have a first surface and a second surface which are positioned so as to sandwich the molded product therebetween and that one electrical cable be provided on each of the first surface and the second surface.
In the imaging module according to the first aspect of the invention, it is preferable that a bend portion which is formed in an extending direction of the molded product be provided so that the angle thereof is greater than a right angle.
In the imaging module according to the first aspect of the invention, it is preferable that the mount surface be provided with a recess-shaped container that fixes the solid-state image sensing device therein.
In the imaging module according to the first aspect of the invention, it is preferable that the surface of the molded product be provided with a groove portion that is used to accommodate the electrical cable therein and extends in an extending direction of the molded product.
In the imaging module according to the first aspect of the invention, it is preferable that the groove portion includes: a groove opening that is located on the same plane as the surface of the molded product and has the width smaller than the diameter of the electrical cable; and an inner groove that is formed inside the groove portion, has a width larger than the width of the groove opening, and accommodates the electrical cable therein.
In the imaging module according to the first aspect of the invention, it is preferable that the electrical cable include a plurality of built-in electrical cables and that groove portions whose number corresponds to the number of the built-in electrical cables be provided.
In the imaging module according to the first aspect of the invention, it is preferable that the groove portion include: a groove opening that is located on the same plane as the surface of the molded product and has the width smaller than the diameter of the built-in electrical cable; and an inner groove that is formed inside the groove portion, has a width larger than the width of the groove opening, and accommodates the built-in electrical cable therein.
In the imaging module according to the first aspect of the invention, it is preferable that the built-in electrical cable be a coaxial cable that is configured to include an internal conductor, a primary coating layer coating the internal conductor, an external conductor provided around the primary coating layer, and a secondary coating layer coating the external conductor, and that the groove portion be provided with step differences that are along the internal conductor exposed at the front end of the built-in electrical cable, the primary coating layer, and the external conductor.
An insulating-tube-attached imaging module according to a second aspect of the invention includes: the imaging module according to the aforementioned first aspect; and an insulating tube that accommodates the imaging module therein.
A lens-attached imaging module according to a third aspect of the invention includes: a sleeve-shaped metal frame member that accommodates: the three-dimensional wiring base and the solid-state image sensing device of the insulating-tube-attached imaging module according to the aforementioned second aspect; and a lens unit fixed to the solid-state image sensing device.
An endoscope according to a fourth aspect of the invention includes: the lens-attached imaging module according to the aforementioned third aspect; and an insertion portion that accommodates the lens-attached imaging module therein.

Effects of the Invention

According to the aspects of the invention, the imaging module includes the above-mentioned constitution; therefore, when the imaging module is inserted into the insulating tube, since the insulating tube comes into contact with two apexes of the three-dimensional wiring base, the imaging module is easily inserted into the insulating tube.
According to the aspects of the invention, it is possible to simply attach the solid-state image sensing device to the right position on the mount surface by using the two apexes of the mount surface as alignment marks.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a side view showing an imaging module A according to one embodiment of the invention and structures of an insulating-tube-attached imaging module B and a lens-attached imaging module C which are configured by use of the imaging module A.

FIG. 1B is a side view showing an imaging module A according to one embodiment of the invention and structures of an insulating-tube-attached imaging module B and a lens-attached imaging module C which are configured by use of the imaging module A.

FIG. 2 is a cross-sectional view showing a configuration which is adjacent to a mount surface 21 a of a three-dimensional wiring base 2 according to one embodiment of the invention.

FIG. 3A is a view showing a shape of the mount surface 21 a of the three-dimensional wiring base 2 according to one embodiment of the invention.

FIG. 3B is a view showing

wirings

22 a, 22 b, 22 c, 22 d, 22 e, 22 f, and 22 g formed on the mount surface 21 a.

FIG. 4A is a schematic view showing a groove portion 21 b formed on a molded product 21 of the three-dimensional wiring base 2 according to one embodiment of the invention.

FIG. 4B is a schematic view showing a groove portion 21 b formed on a molded product 21 of the three-dimensional wiring base 2 according to one embodiment of the invention and is a view showing the groove portion 21 b as seen in the j direction.

FIG. 4C is a schematic view showing a groove portion 21 b formed on a molded product 21 of the three-dimensional wiring base 2 according to one embodiment of the invention and is a view showing the groove portion 21 b as seen in the g direction.

FIG. 5 is a view showing an example of a cross-section structure of the electrical cable 3 according to one embodiment of the invention.

FIG. 6 is a view explaining an endoscope D according to one embodiment of the invention and is an enlarged perspective view showing the tube end thereof.

FIG. 7 is a view showing a configuration of a mount surface serving as a modified example according to the embodiment of the invention.

FIG. 8 is a cross-sectional view showing a container serving as a modified example according to the embodiment of the invention which fixes a solid-state image sensing device therein.

FIG. 9A is a perspective view showing a groove serving as a modified example according to the embodiment of the invention which fixes an electrical cable therein.

FIG. 9B is a cross-sectional view showing a groove serving as a modified example according to the embodiment of the invention which fixes an electrical cable therein and is a view showing a state before the electrical cable is inserted into the groove.

FIG. 9C is a cross-sectional view showing a groove serving as a modified example according to the embodiment of the invention which fixes an electrical cable therein and is a view showing a state after the electrical cable is inserted into the groove.

DETAILED DESCRIPTION OF THE INVENTION

An imaging module A according to the embodiment is a small image-sensing device used in an endoscope and is configured to include: a solid-state image sensing device 1; three-dimensional wiring base 2; and an electrical cable 3 as shown in FIGS. 1A and 1B.
Moreover, as shown in drawings, such an imaging module A is accommodated in an insulating tube 7 and configures an insulating-tube-attached imaging module B.
Furthermore, as shown in drawings, a lens-attached imaging module C is configured of the aforementioned insulating-tube-attached imaging module B, a cover member 4 that is fixed to the solid-state image sensing device 1, a lens unit 5 (object lens unit), and a metal frame member 6 that is formed in a sleeve-shape such as a cylindrical shape in combination.
The solid-state image sensing device 1 is a semiconductor imaging sensor such as a CCD (Charge Coupled Device) chip or a CMOS (Complementary Metal Oxide Semiconductor) chip, and is fixed on a mount surface 21 a of a molded product 21 of the three-dimensional wiring base 2 which will be described later.
The above-described solid-state image sensing device 1 has a top face (light-receiving face) on which a light receiving portion receiving external light is mounted and a back surface that is opposite to the top face.
The solid-state image sensing device 1 is provided with bumps 12 (terminals) such as solder bump which is provided on the back surface and is electrically connected to an electrical circuit provided inside the solid-state image sensing device 1, a stud bump, or a plated bump.
For example, as shown in FIG. 2, the solid-state image sensing device 1 includes a through-hole interconnection 16 (through-hole wiring) that is formed inside a through hole 13 penetrating through the solid-state image sensing device 1 in the plate-thickness direction thereof and is electrically connected to wirings 14 and 15 provided on both the top and back surfaces of the solid-state image sensing device 1.
Moreover, as the solid-state image sensing device used in the embodiment, a back-side Illumination CMOS image sensor (BSI: Back-side Illumination type) may be used.
Similarly, in the back-side Illumination CMOS image sensor, a wiring can be drawn via the through-hole interconnection to the surface that is opposite to the light-receiving face.
Furthermore, by a flip-chip method, via the bump 12, the solid-state image sensing device 1 is connected and fixed to a terminal 21T (refer to FIG. 2) formed on the mount surface 21 a of the three-dimensional wiring base 2.
The solid-state image sensing device 1 is electrically connected to wirings 22 a, 22 b, 22 c, 22 d, 22 e, 22 f, and 22 g the three-dimensional wiring base 2 which will be described later, and is mounted on the mount surface 21 a of the three-dimensional wiring base 2.
The three-dimensional wiring base 2 is a wiring base that is used to stereoscopically package an electronic component thereonto, and is constituted of seven wirings 22 a, 22 b, 22 c, 22 d, 22 e, 22 f, and 22 g formed on the molded product 21 or the surface of the molded product 21. The molded product is made of a resin (PEEK (polyetheretherketone), LCP (Liquid Crystal Polymer)), ceramic, or the like, which have a heat resistance with respect to heat generated when soldering is carried out.
Particularly, the aforementioned soldering is carried out when the wirings 22 a, 22 b, 22 c, 22 d, 22 e, 22 f, and 22 g are connected to the electrical cable 3.
As described above, the above-mentioned molded product 21 is made of a resin (a PEEK material or an LCP material), ceramic, or the like, which have a heat resistance with respect to heat generated when soldering is carried out, and is molded by use of a die or the like.
The foregoing molded product 21 is formed in a shape that extends in the axis direction (a direction perpendicular to the mount surface 21 a which will be described later) of a built-in electrical cable 31 exposed at the front end of the electrical cable 3 which will be described later.
Additionally, regarding the molded product 21, the mount surface 21 a on which the solid-state image sensing device 1 is to be mounted is molded in a hexagonal shape as shown in FIGS. 3A and 3B.
Furthermore, as shown in FIGS. 4A to 4C, four groove portions 21 b are provided on the surface of the molded product 21 along the extending direction of the molded product 21 and are used to accommodate the built-in electrical cable 31 of the electrical cable 3 described later therein.
On the other hand, the seven wirings 22 a to 22 g are provided on the surface of the molded product 21.
Each of the above-described wirings 22 a to 22 g has a first end and a second end.
Particularly, one of ends (first end) provided on the mount surface 21 a is the terminal 21T (FIG. 2) that is connected to the solid-state image sensing device 1, and the other of ends (second end) is the terminal that is connected to the built-in electrical cable 31 of the electrical cable 3 which will be described later.
That is, the solid-state image sensing device 1 is electrically connected to the electrical cables 31 with the wirings 22 a to 22 g interposed therebetween.
In addition, regarding the wirings 22 a to 22 g, the portions other than the terminals are coated with a resin having electrical insulation.
Moreover, the three-dimensional wiring base 2 including the aforementioned molded product 21 and the wirings 22 a to 22 g will be particularly described below.
The electrical cable 3 is used to electrically connect an external device (for example, a display device or the like, not shown in the figure) to the solid-state image sensing device 1 and is a cable unit includes a plurality of built-in electrical cables 31 (four cables shown as an example in the drawing) and an outer coating 32 as shown in FIG. 5.
The built-in electrical cable 31 is a coaxial cable and is configured to include an internal conductor 31 a, a primary coating layer 31 c that coats the internal conductor 31 a, an external conductor 31 b that is formed of a metal thin wire and is provided around the primary coating layer 31 c, and a secondary coating layer 31 d that coats the external conductor 31 b.
The above-described built-in electrical cable 31 is exposed at the outer coating 32 and at the front end of the electrical cable 3.
Additionally, as shown in FIGS. 1A and 1B, the internal conductor 31 a, the primary coating layer 31 c, and the external conductor 31 b are exposed at the front end of the built-in electrical cable 31 which is exposed at the outer coating 32.
The internal conductor 31 a and the external conductor 31 b of the foregoing four built-in electrical cables 31 are connected to any of the aforementioned wirings 22 a to 22 g.
As a result, the solid-state image sensing device 1 is electrically connected to the electrical cable 31 via the wirings 22 a to 22 g.
Moreover, the internal conductor 31 a and the external conductor 31 b of the built-in electrical cable 31 are connected to the wirings 22 a to 22 g by solder or an electroconductive adhesive which is not shown in the figure.
In contrast, the outer coating 3 is made of a predetermined resin and collectively coats a plurality of the built-in electrical cables 31.
The insulating tube 7 is provided to electrically insulate, from the outside thereof, connectors that connect the wirings 22 a to 22 g to the internal conductor 31 a and the external conductor 31 b of the built-in electrical cables 31.
The insulating tube 7 accommodates the imaging module A therein as shown in drawings.
Furthermore, the insulating tube 7 is integrally fixed to the solid-state image sensing device 1, the three-dimensional wiring base 2, and the built-in electrical cables 31, which are provided thereinside, by use of a resin 8 that is cured and fills the inside thereof.
Consequently, the connectors that connect the wirings 22 a to 22 g to the internal conductor 31 a and the external conductor 31 b of the built-in electrical cables 31 are not in contact with the metal frame member 6 and are not short-circuited thereto.
The cover member 4 is a plate-shaped transparent member that covers the light receiving portion of the solid-state image sensing device 1.
For example, the cover member 4 is a transparent plate-shaped member made of a glass or a resin.
The lens unit 5 has a structure in which an object lens (not shown in the figure) is incorporated into a cylindrical lens barrel 5 a.
The lens unit 5 is positionally-fixed to the optical axis of the light receiving portion of the solid-state image sensing device 1 and is provided so that one end of the lens barrel 5 a in the axis direction thereof is fixed to the cover member 4.
The lens unit 5 is configured to provide an image on the light receiving portion of the solid-state image sensing device 1 by guiding light from the opposite side of the cover member 4 through the lenses inside the lens barrel 5 a.
The metal frame member 6 is adhesively-fixed to the insulating tube 7 by a resin 9 that is cured and fills the inside of the metal frame member 6.
The foregoing metal frame member 6 accommodates not only the solid-state image sensing device 1 and the three-dimensional wiring base 2 of the imaging module A but also the built-in electrical cables 31 therein.
Particularly, the portion covered with the outer coating 3 of the electrical cable 1 is disposed outside the metal frame member 6. On the other hand, the built-in electrical cables 31 which are exposed at the outer coating 3 of the electrical cable 1 are drawn into the metal frame member 6.
Additionally, the aforementioned insulating-tube-attached imaging module B and an insertion portion 50 that accommodates the insulating-tube-attached imaging module B therein, in combination, configure an endoscope D.
The aforementioned endoscope D is configured to include: a lumen 51 (first lumen) in the insertion portion 50 that accommodates the lens-attached imaging module B therein; and a lumen 53 (second lumen) that accommodates an optical fiber 52 for illuminating light (light guide).
As a specific example of the lens-attached imaging module, a lens-attached imaging module C was manufactured as a prototype by use of a flat plate-shaped solid-state image sensing device 1 having 0.75 mm square, a three-dimensional wiring base 2 of which the mount surface 21 a has a maximum width of 1.00 mm or less, an insulating tube 7 made of silicone and having an outer diameter of 1.05 mm, a cylindrical metal frame member 6 having an outer diameter of 1.2 mm.
Moreover, an outer diameter of the insertion portion of the endoscope D that is manufactured as a prototype by use of the lens-attached imaging module C was 5 mm.
Next, the three-dimensional wiring base 2 of the imaging module A will be particularly described.
Firstly, a manufacturing process of the three-dimensional wiring base 2 will be described.
In the manufacturing process, initially, the molded product 21 is formed.
That is, as a result of causing a resin (a PEEK material or an LCP material), ceramic, or the like, which have a heat resistance with respect to heat generated when soldering is carried out, to flow into a die used to cast the molded product 21, the molded product 21 having a predetermined shape is formed.
Additionally, the entire surface of the molded product 21 is plated by copper (Cu), and the three-dimensional wiring base 2 is manufactured by drawing a wiring pattern by laser.
The three-dimensional wiring base 2 according to the embodiment which is manufactured through the above-mentioned manufacturing process has three distinct configurations.
The first characteristic point is as follows.
The mount surface 21 a of the three-dimensional wiring base 2 on which the solid-state image sensing device 1 is to be mounted is molded in a hexagonal shape as shown in FIGS. 3A and 3B.
On the above-described mount surface 21 a, the distance between two apexes P1 and P2 of six apexes of the hexagonal shape, which are opposed to each other so as to sandwich the center portion, is the longest in the distances between two points located on the sides H1 of the mount surface 21 a.
That is, the line segment L1 between the apexes P1 and P2 is the longest in the line segments that are present on the mount surface 21 a and includes the diagonal line between other apexes, the line segment L2 orthogonal to the line segment L1 shown in
FIG. 3A, or the like.
Furthermore, a cross-sectional face parallel to the mount surface 21 a of the three-dimensional wiring base 2 is equal to the mount surface 21 a or smaller than the mount surface 21 a.
That is, the three-dimensional wiring base 2 is formed in a shape that has the mount surface 21 a serving as the front end thereof and extends in a direction vertical to the mount surface 21 a so that the peripheral surface of the three-dimensional wiring base 2 does not protrude from the region of the mount surface 21 a when seen in a plan view of the mount surface 21 a.
Furthermore, in the solid-state image sensing device 1, the longest distance between two points on the side H2 of the shape of the solid-state image sensing device 1 in a plan view is equal to or shorter than that between the two apexes P1 and P2 of the mount surface 21 a.
In short, the diagonal line L3 between the apexes of the shape (tetragon) in a plan view of the solid-state image sensing device 1 shown in FIG. 3B is equal to or shorter than that between the two apexes P1 and P2 of the mount surface 21 a.
As described above, the mount surface 21 a has two opposed apexes P1 and P2 which sandwich the central portion therebetween and is molded so that the line segment between two apexes P1 and P2 is the longest in line segments on the mount surface 21 a; the cross section parallel to the mount surface 21 a of the three-dimensional wiring base 2 is equal to the mount surface 21 a or smaller than the mount surface; and the line segment of the shape of the solid-state image sensing device 1 in a plan view is shorter than that between the two apexes P1 and P2 of the mount surface 21 a.
Consequently, when the imaging module A is inserted into the insulating tube 7, the insulating tube 7 is in a state of being in contact with the two apexes P1 and P2 of the three-dimensional wiring base 2; that is, since the region which comes into contact with the insulating tube 7 is narrow, the imaging module A is easily inserted into the insulating tube 7.
Next, the distinct configuration according to the second characteristic point regarding the three-dimensional wiring base 2 will be described.
The molded product 21 of the three-dimensional wiring base 2 has a linear portion 21 e that extends in the extending direction thereof and an inclined portion 21 f inclined with respect to the linear portion 21 e.
An angle of a bend portion 21 c of the molded product 21 that is formed in the extending direction (angle between the linear portion 21 e and the inclined portion 21 f) is greater than the right angle.
That is, the bend portion 21 c is not formed at a sharp angle such as 90 degrees or less and is formed at an obtuse angle such as 90 degrees or more.
As a result, since the wirings 22 a to 22 g that are arranged in the extending direction of the three-dimensional wiring base 2 are not bent at a sharp angle such as the right angle or less, it is possible to prevent wire breakage.
Next, the distinct configuration according to the third characteristic point regarding the three-dimensional wiring base 2 will be described.
The groove portions 21 b are provided on the surface of the molded product 21 and extend in the extending direction of the molded product 21 to accommodate the electrical cable 3 therein.
That is, the groove portions 21 b are provided so that the number thereof (four) corresponds to that of the built-in electrical cables 31.
Moreover, as shown in FIGS. 4A to 4C, in the groove portion 21 b, step differences 21D are provided so as to correspond to the configuration of the internal conductor 31 a that is exposed at the front end of the built-in electrical cable 31 and to the configurations of the primary coating layer 31 c and the external conductor 31 b.
Consequently, it is possible to attach the built-in electrical cables 31 to the right position on the three-dimensional wiring base 2.
Moreover, since the built-in electrical cables 31 can be easily attached to the three-dimensional wiring base 2 by the aforementioned configuration, it is possible to omit time and effort during attachment.
In the above-described embodiment, the mount surface 21 a has two opposed apexes P1 and P2 which sandwich the central portion therebetween and is molded so that the line segment between two apexes P1 and P2 is the longest in line segments on the mount surface 21 a; the cross section parallel to the mount surface 21 a of the three-dimensional wiring base 2 is equal to the mount surface 21 a or smaller than the mount surface; and the line segment of the shape of the solid-state image sensing device 1 in a plan view is shorter than that between the two apexes P1 and P2 of the mount surface 21 a.
Because of this, when the imaging module A is inserted into the insulating tube 7, the insulating tube 7 is in a state of being in contact with the two apexes P1 and P2 of the three-dimensional wiring base 2; that is, since the surface area which comes into contact with the insulating tube 7 is smaller than that of a conventionally cylindrical-shaped three-dimensional wiring base, the imaging module A is easily inserted into the insulating tube 7.
In order to mount the solid-state image sensing device 1 onto the mount surface 21 a of the three-dimensional wiring base 2 with a high level of positional accuracy, an alignment mark is formed on the mount surface 21 a in advance, and it is necessary to carry out the mounting step while adjusting the positional relationship between the alignment mark and the solid-state image sensing device 1.
However, in the case of providing the alignment mark on the mount surface 21 a, it is necessary to make the three-dimensional wiring base 2 larger by the amount of the space on which the alignment mark is formed.
According to the embodiment, the two apexes P1 and P2 on the mount surface 21 a can be used as the alignment mark.
For this reason, without providing an alignment mark on the mount surface 21 a, it is possible to attach the solid-state image sensing device 1 to the right position on the mount surface 21 a.
In addition, according to the embodiment, since the molded product 21 is provided so that the angle of the bend portion 21 c formed in the extending direction is greater than the right angle, the wirings 22 a to 22 g that are provided along the extending direction of the three-dimensional wiring base 2 are not bent at a sharp angle such as a right angle or less.
As a result, it is possible to prevent wire breakage.
Furthermore, according to the embodiment, the groove portions 21 b are provided and extend in the extending direction of the molded product 21 to accommodate the built-in electrical cables 31 therein.
Consequently, it is possible to attach the built-in electrical cables 31 to the right position on the three-dimensional wiring base 2; in addition to this, since the built-in electrical cables 31 can be easily attached to the three-dimensional wiring base 2, it is possible to omit time and effort during attachment.
As described above, the embodiment of the invention is explained; however, the invention is not limited to the above-mentioned embodiment, for example, the following modification is conceivable.
The endoscope D according to the embodiment of the invention accommodates the imaging module A along with the lens unit 5 fixed to the solid-state image sensing device 1 in the sleeve-shaped metal frame member 6.
As long as the imaging module is the imaging module according to the embodiment of the invention, it is not particularly limited.
Additionally, the mount surface 21 a is molded in a hexagonal shape in the embodiment, the invention is not limited to this.
As long as the mount surface 21 a is compliant with the aforementioned conditions, a polygonal shape other than a hexagonal shape may be adopted and a shape other than a polygonal shape may be adopted.
Moreover, the step differences 21D that are along the shapes of the internal conductor 31 a, the primary coating layer 31 c, and the external conductor 31 b are provided in the groove portion 21 b in the embodiment; however, the step differences 21D may not be provided.
For example, the internal conductor 31 a, the primary coating layer 31 c, and the external conductor 31 b may be pressed into and accommodated in groove portions 21 b in which the step differences 21D are not provided.
Furthermore, the groove portion 21 b may be designed to receive the electrical cable 3 that accommodates the built-in electrical cables 31 therein.

Modified Example

Next, modified examples of the above-described embodiment will be described with reference to FIGS. 7 to 9C.
FIGS. 7 to 9C, identical reference numerals are used for the elements which are identical to those of the aforementioned embodiment, and the explanations thereof are omitted or simplified here.
In a modified example shown in FIG. 7, the shape of a mount surface 41 a is a rectangular shape, and a molded product 41 is formed in a plate shape.
Specifically, the molded product 41 has a first surface 42 a and a second surface 42 b located on the opposite side of the first surface 42 a, which are located so as to sandwich the molded product 41 therebetween.
One electrical cable is provided on each of the first surface 42 a and the second surface 42 b.
That is, an electrical cable 43 a is provided on the first surface 42 a, and an electrical cable 43 b is provided on the second surface 42 b.
A bump of the solid-state image sensing device is connected and fixed to a terminal which is formed on the mount surface as shown in FIG. 2.
The solid-state image sensing device is electrically connected to the electrical cables 43 a and 43 b which are provided on the first surface 42 a and the second surface 42 b, respectively, and the image sensing device is mounted on the mount surface 41 a.
In other cases, a groove portion that accommodates a built-in electrical cable of an electrical cable therein may be provided on the first surface 42 a and the second surface 42 b in the extending direction of the molded product 41.
In a modified example shown in FIG. 8, a recess-shaped container 46 that causes the solid-state image sensing device 1 to be fixed to a mount surface 45 a of a molded product 45 is provided.
The container 46 is provided on the mount surface 45 a so as to surround the solid-state image sensing device 1; as the solid-state image sensing device 1 is disposed inside the container 46, the positioning of the solid-state image sensing device 1 is carried out, and the terminal 21T formed on the mount surface 45 a is reliably connected to the bump 12 of the solid-state image sensing device 1 (refer to FIG. 2).
In other cases, a wiring extending from the terminal 21T toward the electrical cable may be formed along the surface of the container 46 and may be connected to the electrical cable through a cut-off portion that is partially provided on the container 46.
Moreover, FIG. 8 shows a structure in which part of the container 46 (outer surface) forms the external face of the molded product 45; however, the invention is not limited to the above-described configuration.
For example, a container may be formed between the wirings 22 a and 22 b, between the wirings 22 b and 22 c, between the wirings 22 d and 22 e, and between the wirings 22 f and 22 g which are shown in FIG. 3B so as to protrude from the mount surface.
In other words, a container may be formed between wirings adjacent to each other formed on the mount surface.
In this case, it is preferable that the solid-state image sensing device 1 be in contact with the container at at least three portions and that the position of the solid-state image sensing device 1 be aligned.
FIGS. 9A to 9C show a modified example of the groove portion 21 b that is provided along the extending direction of the molded product 21.
In the modified example described below, “width” means a length in a direction orthogonal to the extending direction of the groove portion 21 b, “width direction” means a direction orthogonal to the extending direction of the groove portion 21 b.
The groove portion 21 b has a groove opening 21 g and an inner groove 21 h and is formed on the surface 21 d of the molded product 21.
The groove opening 21 g is located on the same plane as the surface 21 d of the molded product 21.
The inner groove 21 h opens at the groove opening 21 g and is formed inside the groove portion 21 b.
The width 21 w of the groove opening 21 g (distance between ends of the groove opening 21 g) is smaller than the width 3 w of the electrical cable 3 (diameter).
Furthermore, the width 21 x of the inner groove 21 h is larger than the width 21 w of the groove opening 21 g.
Here, the width 21 w of the groove opening 21 g is set to the width of the electrical cable 3 when the electrical cable 3 is constricted by elastic deformation in the width direction.
That is, the width 21 w is substantially equal to the width of the electrical cable 3 which is obtained when the diameter thereof is reduced by elastic deformation.
Additionally, the width 21 x of the inner groove 21 h is determined based on the width 3 w of the electrical cable 3 so that the electrical cable 3 can be accommodated in the groove portion 21 b.
For example, the width 21 x of the inner groove 21 h may be substantially the same as the width 3 w that is obtained after the elastically-deformed electrical cable 3 is restored to the original state inside the inner groove 21 h.
Moreover, in order to stably hold the electrical cable 3 in the inner groove 21 h, the width 21 x may be slightly smaller than the width 3 w.
As shown in FIG. 9A showing a perspective view and FIG. 9B showing a cross-sectional view, when the electrical cable 3 is inserted into the inner groove 21 h through the groove opening 21 g, the electrical cable 3 is pressed onto the surface 21 d so as to face the groove portion 21 b in the direction indicated by reference letter Q.
Since the width 3 w is larger than the width 21 w, when the electrical cable 3 comes into contact with the ends of the groove opening 21 g and is pressed toward the inner groove 21 h, the electrical cable 3 is elastically deformed while being pressed by the ends of the groove opening 21 g, and the width 3 w is reduced.
Thereafter, the electrical cable 3 passes through the groove opening 21 g and reaches the inner groove 21 h, and an elastic deformation state of the electrical cable 3 is released.
As shown in FIG. 9C showing a cross-sectional view, in the inner groove 21 h, the shape of the electrical cable 3 is restored to the original state, and the electrical cable 3 is accommodated in the inner groove 21 h.
In this state, since the width 21 w of the groove opening 21 g is smaller than the width 3 w of the electrical cable 3, the electrical cable 3 is prevented from being removed from the inner groove 21 h.
In the aforementioned modified example, FIG. 9C shows a state where the electrical cable 3 is accommodated in the inner groove 21 h; however, part of the electrical cable 3 may protrude from the groove opening 21 g while a holding state of the electrical cable 3 is maintained.
Furthermore, as shown in FIGS. 9B and 9C, the shape of the inner groove 21 h is a substantially circular shape (a shape in which a circle is cut-off by the groove opening 21 g); however, it is not limited to this shape, and a rectangular shape may be adopted.
The shape and the dimensions of the inner groove 21 h are suitably determined based on the shape and the dimensions of the electrical cable 3 or depending on a holding state of the electrical cable 3.
Additionally, the groove opening 21 g having the width 21 w smaller than the width 21 x of the inner groove 21 h is not necessarily formed on the entire formation area of the groove portion 21 b.
This means that, it is only necessary to partially form a plurality of groove opening 21 g along the formation area of the groove portion 21 b (extending direction).
In this case, the groove openings 21 g may be formed at suitable positions in the extending direction of the groove portion 21 b so that the electrical cable 3 is prevented from being removed from the inner groove 21 h.
The space between the formed groove openings 21 g may be an equal interval.
Furthermore, the groove opening 21 g may be formed at the position at which the electrical cable 3 is easily removed from the groove portion 21 b.
In the above-mentioned embodiment, the groove portions 21 b are provided in the extending direction of the molded product 21 so that the number thereof (four) corresponds to that of the built-in electrical cables 31.
The invention is not limited to the above-described configuration, the built-in electrical cable 31 may be provided in the groove portion 21 b having the groove opening 21 g and the inner groove 21 h shown in FIGS. 9A to 9C.
In this case, instead of the electrical cable 3 shown in FIGS. 9A to 9C, the built-in electrical cable 31 is inserted into the inner groove 21 h through the groove opening 21 g, and the built-in electrical cable 31 is held by the inner groove 21 h.
Here, the inner groove 21 h opens at the groove opening 21 g and is formed inside the groove portion 21 b.
The width 21 w of the groove opening 21 g (the distance between the ends of the groove opening 21 g) is smaller than the width (diameter) of the built-in electrical cable 31.
Additionally, the width 21 x of the inner groove 21 h is larger than the width 21 w of the groove opening 21 g.
In this state, since the width 21 w of the groove opening 21 g is smaller than the width of the built-in electrical cable 31, the built-in electrical cable 31 is prevented from being removed from the inner groove 21 h.
While preferred embodiments of the invention have been described and shown above, it should be understood that these are exemplary of the invention and are not to be considered as limiting. Additions, omissions, substitutions, and other modifications can be made without departing from the scope of the present invention. Accordingly, the invention is not to be considered as being limited by the foregoing description, and is only limited by the scope of the appended claims.

Claims

What is claimed is:

1. An imaging module comprising:

an electrical cable;

a solid-state image sensing device having a light-receiving face perpendicular to an axis direction of a front end of the electrical cable; and

a three-dimensional wiring base in which a wiring is formed on a surface of a molded product extending in the axis direction, the electrical cable is electrically connected to the solid-state image sensing device via the wiring, and a mount surface used to package the solid-state image sensing device thereon is provided on a front end of the molded product, wherein

the mount surface has two opposed apexes which sandwich a central portion therebetween and is molded so that a distance between the two apexes is the longest in distances between two points on sides of the mount surface, a cross section parallel to the mount surface of the three-dimensional wiring base is equal to the mount surface or smaller than the mount surface, and a distance between two points that is the longest in distances on sides of a shape in a plan view of the solid-state image sensing device is equal to or shorter than the distance between the two apexes.

2. The imaging module according to claim 1, wherein

the mount surface is formed in a hexagonal shape.

3. The imaging module according to claim 1, wherein

the molded product has a first surface and a second surface which are positioned so as to sandwich the molded product therebetween, and one electrical cable is provided on each of the first surface and the second surface.

4. The imaging module according to claim 1, wherein

a bend portion which is formed in an extending direction of the molded product is provided so that an angle thereof is greater than a right angle.

5. The imaging module according to claim 4, wherein

the mount surface is provided with a recess-shaped container that fixes the solid-state image sensing device therein.

6. The imaging module according to claim 1, wherein

the surface of the molded product is provided with a groove portion that is used to accommodate the electrical cable therein and extends in an extending direction of the molded product.

7. The imaging module according to claim 6, wherein

the groove portion comprises:

a groove opening that is located on the same plane as the surface of the molded product and has a width smaller than a diameter of the electrical cable; and

an inner groove that is formed inside the groove portion, has a width larger than a width of the groove opening, and accommodates the electrical cable therein.

8. The imaging module according to claim 6, wherein

the electrical cable includes a plurality of built-in electrical cables, and

groove portions whose number corresponds to the number of the built-in electrical cables are provided.

9. The imaging module according to claim 8, wherein

the groove portion comprises:

a groove opening that is located on the same plane as the surface of the molded product and has a width smaller than a diameter of the built-in electrical cable; and

an inner groove that is formed inside the groove portion, has a width larger than a width of the groove opening, and accommodates the built-in electrical cable therein.

10. The imaging module according to claim 8, wherein

the built-in electrical cable is a coaxial cable that is configured to include an internal conductor, a primary coating layer coating the internal conductor, an external conductor provided around the primary coating layer, and a secondary coating layer coating the external conductor, and

the groove portion is provided with step differences that are along the internal conductor exposed at a front end of the built-in electrical cable, the primary coating layer, and the external conductor.

11. An insulating-tube-attached imaging module comprising:

the imaging module according to claim 1; and

an insulating tube that accommodates the imaging module therein.

12. A lens-attached imaging module comprising

a sleeve-shaped metal frame member that accommodates: the three-dimensional wiring base and the solid-state image sensing device of the insulating-tube-attached imaging module according to claim 11; and a lens unit fixed to the solid-state image sensing device.

13. An endoscope comprising:

the lens-attached imaging module according to claim 12; and

an insertion portion that accommodates the lens-attached imaging module therein.